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Hello Linux Kernel community, We encountered a crash bug when testing the driver implemented in `drivers/md/dm-ioctl.c` by using Syzkaller. Notably, we generate the spec for this driver by ourselves and Syzkaller doesn’t have specification for it. Based on our understanding, this bug is caused by `dmi = kvmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH);` in ` drivers/md/dm-ioctl.c` (https://github.com/torvalds/linux/blob/3bd7d748816927202268cb335921f7f68b3ca723/drivers/md/dm-ioctl.c#L1966), which `kvmalloc` a size more than INT_MAX. A possible patch is to have a more strict check for the `param_kernel->data_size` in `copy_params` before calling `kvmalloc` while currently it only checks minimal size (https://github.com/torvalds/linux/blob/3bd7d748816927202268cb335921f7f68b3ca723/drivers/md/dm-ioctl.c#L1944). We reproduced this bug in the latest Linux Kernel (reproducible on 3bd7d748816927202268cb335921f7f68b3ca723 and found on d2f51b3516dade79269ff45eae2a7668ae711b25), and the config for the kernel is attached. Here is the log and Syzkaller reproducer. C reproducer is also attached, which can compiled by `gcc -pthread`. Syzkaller hit 'WARNING: kmalloc bug in ctl_ioctl' bug. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 8924 at mm/util.c:622 kvmalloc_node+0x194/0x1a0 mm/util.c:622 Modules linked in: CPU: 1 PID: 8924 Comm: syz-executor401 Not tainted 6.6.0-gd2f51b3516da #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:kvmalloc_node+0x194/0x1a0 mm/util.c:622 Code: a2 3f 1c 00 eb aa e8 ab 40 c9 ff 41 81 e5 00 20 00 00 31 ff 44 89 ee e8 ba 3c c9 ff 45 85 ed 0f 85 1b ff ff ff e8 8c 40 c9 ff <0f> 0b e9 e3 fe ff ff 0f 1f 44 00 00 f3 0f 1e fa
41 55 49 89 f5 41 RSP: 0018:ffffc900025d7c90 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000400 RCX: ffffffff81b9bd56 RDX: ffff888043d13c00 RSI: ffffffff81b9bd64 RDI: 0000000000000005 RBP: 00000000fffffff7 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007fd044e9f640(0000) GS:ffff88807ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd044e9f658 CR3: 000000001ed0d000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> kvmalloc include/linux/slab.h:738 [inline] copy_params drivers/md/dm-ioctl.c:1966 [inline] ctl_ioctl+0x5a7/0xad0 drivers/md/dm-ioctl.c:2070 dm_ctl_ioctl+0x25/0x30 drivers/md/dm-ioctl.c:2103 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x19d/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3f/0xe0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7fd044f1657d Code: c3 e8 37 20 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff
f7 d8 64 89 01 48 RSP: 002b:00007fd044e9f1b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd044fb1218 RCX: 00007fd044f1657d RDX: 0000000020001a40 RSI: 00000000c138fd02 RDI: 0000000000000003 RBP: 00007fd044fb1210 R08: 00007ffd74b7727f R09: 00007fd044e9f640 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd044fb121c R13: 0000000000000000 R14: 00007fd044ede720 R15: 00007fd044e7f000 </TASK> Syzkaller reproducer: # {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false
KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Repro:false Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}} r0 = openat$dm_ctl(0xffffffffffffff9c, &(0x7f0000001740), 0x2, 0x0) ioctl$DM_LIST_DEVICES(r0, 0xc138fd02, &(0x7f0000001a40)={[0x80, 0x2, 0x8], 0xfffffff7, 0x4, 0xffffffff, 0x1, 0x0, 0x401, 0xb343, 0x5, "68e13bcbb7a06fdc850a413ee671d60fd199aaae3192593434175f393a0b4871b1face608d1c03b8b8e15d908f68279d4f1f54dcf69536a0319bc51d054ebaa2c7f46138fa96f653c6c4eb53df16d75adc3c325c80a5d7c1716c3d64f1d2b45981bdb014925e83a657036110d1fa84f48b1f3061c08ebee460bcfedd9b64150a",
"e1b2729c21d9ccf8272995c702bc273fc3498e8ae2dbaf0dcbbaeffa78586e234bacc0ac62fd6f628d162e65c1b9dcb78ab0a713f999bd28558eeece0bb9fbe721be74f153bd73d2ba2d405dddde4efc53ebfad5e02432f94ae6dc4153aca6fd3363ee9bb0c13dbf45349dd21bb09751bbd36317bc36e10c84a9d2a9fb491eb1f9",
"2d583a0bcd8671"}) (async) ioctl$DM_LIST_DEVICES(r0, 0xc138fd02, &(0x7f0000001a40)={[0x80, 0x2, 0x8], 0xfffffff7, 0x4, 0xffffffff, 0x1, 0x0, 0x401, 0xb343, 0x5, "68e13bcbb7a06fdc850a413ee671d60fd199aaae3192593434175f393a0b4871b1face608d1c03b8b8e15d908f68279d4f1f54dcf69536a0319bc51d054ebaa2c7f46138fa96f653c6c4eb53df16d75adc3c325c80a5d7c1716c3d64f1d2b45981bdb014925e83a657036110d1fa84f48b1f3061c08ebee460bcfedd9b64150a", "e1b2729c21d9ccf8272995c702bc273fc3498e8ae2dbaf0dcbbaeffa78586e234bacc0ac62fd6f628d162e65c1b9dcb78ab0a713f999bd28558eeece0bb9fbe721be74f153bd73d2ba2d405dddde4efc53ebfad5e02432f94ae6dc4153aca6fd3363ee9bb0c13dbf45349dd21bb09751bbd36317bc36e10c84a9d2a9fb491eb1f9", "2d583a0bcd8671"}) Best, Chenyuan |
Attachment:
dm-ctl-bug.log
Description: dm-ctl-bug.log
// autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include <dirent.h> #include <endian.h> #include <errno.h> #include <fcntl.h> #include <pthread.h> #include <signal.h> #include <stdarg.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/prctl.h> #include <sys/stat.h> #include <sys/syscall.h> #include <sys/types.h> #include <sys/wait.h> #include <time.h> #include <unistd.h> #include <linux/futex.h> static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void thread_start(void* (*fn)(void*), void* arg) { pthread_t th; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); int i = 0; for (; i < 100; i++) { if (pthread_create(&th, &attr, fn, arg) == 0) { pthread_attr_destroy(&attr); return; } if (errno == EAGAIN) { usleep(50); continue; } break; } exit(1); } typedef struct { int state; } event_t; static void event_init(event_t* ev) { ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { if (ev->state) exit(1); __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000); } static void event_wait(event_t* ev) { while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0); } static int event_isset(event_t* ev) { return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE); } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; for (;;) { uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts); if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) return 1; now = current_time_ms(); if (now - start > timeout) return 0; } } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); } struct thread_t { int created, call; event_t ready, done; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { event_wait(&th->ready); event_reset(&th->ready); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); event_set(&th->done); } return 0; } static void execute_one(void) { int i, call, thread; for (call = 0; call < 3; call++) { for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; event_init(&th->ready); event_init(&th->done); event_set(&th->done); thread_start(thr, th); } if (!event_isset(&th->done)) continue; event_reset(&th->done); th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); event_set(&th->ready); if (call == 1) break; event_timedwait(&th->done, 50); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { setup_test(); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[1] = {0xffffffffffffffff}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: memcpy((void*)0x20001740, "/dev/mapper/control\000", 20); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20001740ul, /*flags=*/2ul, /*mode=*/0ul); if (res != -1) r[0] = res; break; case 1: *(uint32_t*)0x20001a40 = 0x80; *(uint32_t*)0x20001a44 = 2; *(uint32_t*)0x20001a48 = 8; *(uint32_t*)0x20001a4c = 0xfffffff7; *(uint32_t*)0x20001a50 = 4; *(uint32_t*)0x20001a54 = -1; *(uint32_t*)0x20001a58 = 1; *(uint32_t*)0x20001a5c = 0; *(uint32_t*)0x20001a60 = 0x401; *(uint32_t*)0x20001a64 = 0xb343; *(uint64_t*)0x20001a68 = 5; memcpy((void*)0x20001a70, "\x68\xe1\x3b\xcb\xb7\xa0\x6f\xdc\x85\x0a\x41\x3e\xe6\x71\xd6\x0f" "\xd1\x99\xaa\xae\x31\x92\x59\x34\x34\x17\x5f\x39\x3a\x0b\x48\x71" "\xb1\xfa\xce\x60\x8d\x1c\x03\xb8\xb8\xe1\x5d\x90\x8f\x68\x27\x9d" "\x4f\x1f\x54\xdc\xf6\x95\x36\xa0\x31\x9b\xc5\x1d\x05\x4e\xba\xa2" "\xc7\xf4\x61\x38\xfa\x96\xf6\x53\xc6\xc4\xeb\x53\xdf\x16\xd7\x5a" "\xdc\x3c\x32\x5c\x80\xa5\xd7\xc1\x71\x6c\x3d\x64\xf1\xd2\xb4\x59" "\x81\xbd\xb0\x14\x92\x5e\x83\xa6\x57\x03\x61\x10\xd1\xfa\x84\xf4" "\x8b\x1f\x30\x61\xc0\x8e\xbe\xe4\x60\xbc\xfe\xdd\x9b\x64\x15\x0a", 128); memcpy( (void*)0x20001af0, "\xe1\xb2\x72\x9c\x21\xd9\xcc\xf8\x27\x29\x95\xc7\x02\xbc\x27\x3f\xc3" "\x49\x8e\x8a\xe2\xdb\xaf\x0d\xcb\xba\xef\xfa\x78\x58\x6e\x23\x4b\xac" "\xc0\xac\x62\xfd\x6f\x62\x8d\x16\x2e\x65\xc1\xb9\xdc\xb7\x8a\xb0\xa7" "\x13\xf9\x99\xbd\x28\x55\x8e\xee\xce\x0b\xb9\xfb\xe7\x21\xbe\x74\xf1" "\x53\xbd\x73\xd2\xba\x2d\x40\x5d\xdd\xde\x4e\xfc\x53\xeb\xfa\xd5\xe0" "\x24\x32\xf9\x4a\xe6\xdc\x41\x53\xac\xa6\xfd\x33\x63\xee\x9b\xb0\xc1" "\x3d\xbf\x45\x34\x9d\xd2\x1b\xb0\x97\x51\xbb\xd3\x63\x17\xbc\x36\xe1" "\x0c\x84\xa9\xd2\xa9\xfb\x49\x1e\xb1\xf9", 129); memcpy((void*)0x20001b71, "\x2d\x58\x3a\x0b\xcd\x86\x71", 7); syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xc138fd02, /*arg=*/0x20001a40ul); break; case 2: *(uint32_t*)0x20001a40 = 0x80; *(uint32_t*)0x20001a44 = 2; *(uint32_t*)0x20001a48 = 8; *(uint32_t*)0x20001a4c = 0xfffffff7; *(uint32_t*)0x20001a50 = 4; *(uint32_t*)0x20001a54 = -1; *(uint32_t*)0x20001a58 = 1; *(uint32_t*)0x20001a5c = 0; *(uint32_t*)0x20001a60 = 0x401; *(uint32_t*)0x20001a64 = 0xb343; *(uint64_t*)0x20001a68 = 5; memcpy((void*)0x20001a70, "\x68\xe1\x3b\xcb\xb7\xa0\x6f\xdc\x85\x0a\x41\x3e\xe6\x71\xd6\x0f" "\xd1\x99\xaa\xae\x31\x92\x59\x34\x34\x17\x5f\x39\x3a\x0b\x48\x71" "\xb1\xfa\xce\x60\x8d\x1c\x03\xb8\xb8\xe1\x5d\x90\x8f\x68\x27\x9d" "\x4f\x1f\x54\xdc\xf6\x95\x36\xa0\x31\x9b\xc5\x1d\x05\x4e\xba\xa2" "\xc7\xf4\x61\x38\xfa\x96\xf6\x53\xc6\xc4\xeb\x53\xdf\x16\xd7\x5a" "\xdc\x3c\x32\x5c\x80\xa5\xd7\xc1\x71\x6c\x3d\x64\xf1\xd2\xb4\x59" "\x81\xbd\xb0\x14\x92\x5e\x83\xa6\x57\x03\x61\x10\xd1\xfa\x84\xf4" "\x8b\x1f\x30\x61\xc0\x8e\xbe\xe4\x60\xbc\xfe\xdd\x9b\x64\x15\x0a", 128); memcpy( (void*)0x20001af0, "\xe1\xb2\x72\x9c\x21\xd9\xcc\xf8\x27\x29\x95\xc7\x02\xbc\x27\x3f\xc3" "\x49\x8e\x8a\xe2\xdb\xaf\x0d\xcb\xba\xef\xfa\x78\x58\x6e\x23\x4b\xac" "\xc0\xac\x62\xfd\x6f\x62\x8d\x16\x2e\x65\xc1\xb9\xdc\xb7\x8a\xb0\xa7" "\x13\xf9\x99\xbd\x28\x55\x8e\xee\xce\x0b\xb9\xfb\xe7\x21\xbe\x74\xf1" "\x53\xbd\x73\xd2\xba\x2d\x40\x5d\xdd\xde\x4e\xfc\x53\xeb\xfa\xd5\xe0" "\x24\x32\xf9\x4a\xe6\xdc\x41\x53\xac\xa6\xfd\x33\x63\xee\x9b\xb0\xc1" "\x3d\xbf\x45\x34\x9d\xd2\x1b\xb0\x97\x51\xbb\xd3\x63\x17\xbc\x36\xe1" "\x0c\x84\xa9\xd2\xa9\xfb\x49\x1e\xb1\xf9", 129); memcpy((void*)0x20001b71, "\x2d\x58\x3a\x0b\xcd\x86\x71", 7); syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xc138fd02, /*arg=*/0x20001a40ul); break; } } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=*/7ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); loop(); return 0; }
Attachment:
kernel.config
Description: kernel.config
